ML20149E256

Forwards Supplemental Info to Radioactive Liquid Effluent Sys Description Provided Via Ltr Gca 87-763 Dtd 871112,to Support Evaluation of Rev 2 to Proposed Amend 155.Concerns Raised Re Radioactive Liquid Effluent Sys Listed

ML20149E256
Person / Time
Site:	Rancho Seco
Issue date:	01/07/1988
From:	Andognini G SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Miraglia F NRC
References
GCA-87-916, TAC-64735, NUDOCS 8801130278
Download: ML20149E256 (12)

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$SMUD SACRAMENTO MUNICIPAL UT!LITY DISTRICT D 6201 S Street, P.O. Box 15800, Sacramento CA 95852-1830,(916) 452 3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA JAN 0 71988 GCA 87-916 U.S. Nuclear Regulatory Commission Attn: Frank J. Miraglia, Jr.

Associate Director for Projects Philips Building 7920 Norfolk avenue Bethesda, MD 20014 backet No. 50-312 Rancho Seco Nuclear Generating Station License No. DPR-54 RADI0 ACTIVE LIQUID EFFLUENT SYSTEMS DESCRIPTION SUPPLEMENT

Dear Mr. Miraglia:

The District hereby submits supplemental information to the Radioactive Liquid Effluent Systems Description, which was provided to you via letter GCA 87-763 dated 11/12/87, to support the evaluation of Proposed Amendment No.155, Revision 2. The supplemental information presented in Attachment I represents action items identified during the 11/13/87 radiological effluent meeting between tiie District and the NRC at Rancho Seco.

Concerns raised in regards to the Radioactive Liquid Effluent Systems Description and responded to in Attachment I include:

1. Adequacy of the effluent strainer for catching expected resin firas.

2. Design information comparison between expected resin fines size and strainer size.

3. Effect of the filters at the radiation monitor inlets on monitor l readings.

l 4. Effect of sunlight on demineralizer hoses.

! 5. Consideration of radiological aspects of skid mounted equipment l outside the Auxiliary Building.

) 6. Adequacy of snap fittings on the Demineralizer.

6801130270 880107 PDR P ADOCK 05000312 PDR

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i RANCHO SECO NUCLEAR GENERATING STATION D 1444o Twin Cities Road Herald, CA 95638-9799;(209) 333 2935

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GCA 87-916 Frank J. Miraglia, Jr. # N 0 7 1988 Please contact me if have any questions. Members of your staff with questions requiring additional information or clarification may contact Mr. Richard Mannheimer at (209) 333-2935.

Sincerely,

/ Ojn*

G. Carl Andognini Chief Executive Officer, 1 Nuclear Attachment cc: G. Kalman, NRC, Bethesda (w/atch)

A. D'Angelo, NRC, Rancho Seco ( " )

C. Willis, NRC, Bethesda (

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J.B. . Martin, NRC, Region V ( )

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ATTACHMENT 1 RADI0 ACTIVE LIQUID EFFLUENT SYSTEM DESCRIPTION SUPPLEMENT l

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Attachment 1 1 of 9 ACTION ITEM 1:

PROVIDE DESIGN INFORMATION ON EXPECTED SIZE OF RESIN WHICH WILL BE CAUGHT BY EFFLUENT STRAINER PROCESSING. COMPARE WITH HISTORICAL DATA ON RESIN FINES FOUND IN PLANT EFFLUENTS.

RESPONSE

SMUD specifications for commercial grade secondary side domineralizer resin require that the amount of resin passing through a 40 mesh screen be limited to 1.5% of the resin volume. According to resin suppliers contacted, the volure of subsize resin beads beyond 40 mesh decreases rapidly with increasing mesh size (see attached graph). Pass-through at 50 mesh typically can be as low as 0.5%, and at 100 mesh (140 microns) no pass-through of resin particles is expected. No typical particle size distributions are available beyond 50 mesh since particle size distributions vary with manufacturer, type of resin, ,

and batch number.

Fractured beads, which are commonly found in reprocessed or regenerated resin, are not considered to reach the Effluent Strainer since the Sluiceable i Demineralizer beds will be operated in the throw-away mode and be loaded with strong, high crush strength resin. Resin fines in the potentially radioactive process stream from either the 'A' or 'B' RHU1 c3n be removed by the Sluiceable Demineralizer inlet filter which has a Vari 3hle "Scention capability down to 3 microns. The Sluiceable Demineralizer is also followed by a 100 mesh Y-strainer. Both of these filters (pre-filter and af ter-filter), which are associated with the Sluiceable Denineralizer, can prevent resin fines from reaching the effluent Strainer.

Sample analyses of creek sediment have not identified the presence of resin i fines. Find.ags from creek surveys are contained in Lawrence Livermore Lab reports issued to SMUD in 1985,1986, and 1987. SMUD has no historical data 1 on resin fines found in plant effluents or the Retention Basins. Lawrence Livermore Lab

• verbally verified they had seen resin beads in the Retention Rasins, but no resin fines and no dccumentation on the quantity of resin beads exists. Operational changer in Condensate Polishing Demineralizer beds to no regeneration during periods of secondary side contamination, and the directing of all liquids from the Polishing Sump Demineralizers through the Effluent Strainer via the Regenerant Hold-up Tank protect against possible release of radioactively contaminated resin fines into the plant effluent.

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• Basin samples taken by LLNL on S/23/84 and 8/16/84 Reference LLNL Report UCID-20298, pg. No. 4, pg. No.11.

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FIGURE FOR RESPONSE TO ACTION ITDI 1 ATTACHMENT 1

. 2 of e 100-90-80-W E 70 D

.J h FINES : SUBSIZE BEADS g 60- )

<t 1. 5 '/o 0F TOTAL VOLUME IS GREATER o THAN 40 MESH AS SPECIFIED E

& 50-u.

o H 40-2 w I U

$ 30-  ;

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50 %

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20-10-3.5 % l.0 % 0.5 %

0 10 20 30 40 5O 60 7'o 8'O 90 ido MESH I I I I 830 420 220 14 0 RESIN VOLUME DISTRIBUTION BY RESIN BEAD SIZE l 1

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• REFERENCES  ;

(1) SMUD PO RN 87 21744  !

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Attachment 1 3 of 9 RESPONSE: (ACTION ITEM 1 CONTINUED)

Makeup Demineralizer regeneration waste released via the Regenerant Holdup Tank (RHUT C) into the plant effluent may contain non-radioactively contaminated resin fines. These resin fines, when exposed to the potentially radioactively contaminated discharge from the 'A' and 'B' RHUTs, may become radioactively contaminated. The radioactivity level of these resin fines will

, be directly proportional to the radioactivity of the effluent stream. Since I

the radioactivity level of the effluent can range from zero to very low, depending on the source of water, the time average radioactivity concentration of resin fines is not likely to exceed the highest radioactivity levels encountered in the wastewater.

Attachment 1 4 of 9 ACTION ITEM 2:

PROVIDE DESIGN INFORMATION ON STRAINER SIZE OF EFFLUENT DEMINERALIZER.

COMPARE WITH EXPECTED SIZE OF EFFLUENT DEMINERALIZER RESINS / RESIN FINES.

RESPONSE

The plant Effluent Strainer, which is valved to operate and backvash in parallel, consists of 6 tubular filter modules. Current filter elements are 100 mesh (140 microns) 316 SS woven screens which match the particle retention capability of the Sluiceable Demineralizer Y-Strainer that precedes the Effluent Stainer. The retention capability of the Effluent Strainer therefore is considered acceptable because resin fines are not expected to pass through a 100 mesh screen (see response to Action Item 1).

/ttachment 1 5 of 9 ACTION ITEM 3:

PROVIDE DESIGN INFORMATION ON THE EFFECT OF FILTERS AT RADIATION MONITOR INLETS ON THE VALIDITY OF MONITOR READINGS.

RESPONSE

l The three radiatian monitors R-15020, R15017A and R-150178 monitor the Radioactive Liquic Effluent releases. Only two of the three radiation monitors, R-15017A and R-15017B, use a strainer in the sample inlet. Approval of Proposed Amendn nt No.155, Rev. 2 will change the Technical Specification monitor from R-15010 to R-15017A.

A duplex manually bat \ washable strainer is used to renove gross debrir and prevent the monitor f'iow meter from clogging. The strainer element >pening and surface area are 890 microns and 241 square inches, respectively. The elements are selected to ensure that a representative sample is obt.ined. The large openir.gs in the strainer ensure that radioactive material is not retained on the strainer. The element surface area is large enouca to provide at least 10 days of continuous operation between backwashes. Duplex strainer configuration allows uninterrupte6 radiation monitor operation dtring backwashes.

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Attachment 1 6 of 9 ACTION ITEM 4:

PROVIDE DESIGN INFORMATION ON EFFECT OF SUNLIGHT ON DEMINERALIZER H0SES.

RESPONSE

H(ses used for process fluid consist of an inner tube and an external, reinforced, braided stainless steel wire hose. The outer surface is wrapped with fabric tape to protect the metal braiding. The pressure boundary material of the demineralizer hose, ethylene propylene diene (EPDM), is not exposed to sunlight. The external surface of the hose material is rated as "Excellent" against weathering, sunlight, heat, and "Outstanding" against exposure.

The pressure rating of the hose is 250 psig, while the maximum operating pressure at pump shut-off is approximately 100 psig. The hoses were hydrotested at the factory at 1.5 times the rated pressure.

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Attachment 1 7 of 9 ACTION ITEM 5:

PROVIDE DESIGN INFORMATION ON CONSIDERATION OF RADIOLOGICAL ASPECTS OF SKID MOUNTED EQUIPMENT OUTSIDE THE AUXILIARY BUILDING. EVALUATE FAILURE MODES, BERM AND DRAIN SIZING, AND FLOWPATHS. COMPARE RADIOLOGICAL PROTECTIVE i

MEASURES T0 THOSE DESCRIDED IN THE USAR.

RESPONSE

The design modification to the secondary waste system considers potential radioactive contamination. Since the modification included equipment that could concentrate the potential contamination, measures beyond those considered in the original secondary waste system design are implemented.

Among the measures implemented are the following:

. A curb to contain spills and decon water.

. A drain and sump system to collect and redirect spills, i

. A decon facility for equipment washdown.

The skid mounted strainer and demineralizer are within a curbed area which has '

, a retention capacity of 2,000 gallons. This volume is considered more than

adequate to contain any upset or leakage of approximately 50 gpm. The Sluiceable Demineralizer and Effluent Strainer are monitored periodically while the syster, is operating. Pipe or hose failures would be contained ,

through valve operations.

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The drain and sump subsystems can collect leakage or spilled water and pump it i

back to the 'A' or #B' RHUT. This system is designed at 50 gpm which is equivalent to the failure of a 1 1/2 inch line.  !

A decon facility for washdown of demineralizer resin casks prior to shipment

is provided. This washdown water, at approximately 20 gpm, is directed to the drain and sump subsystems.

i Shielding of the strainer and demineralizer is not considered necessary due to i the low levels of potential contamination.

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Attachment 1

• 3 8 of 9 RESPONSE: (ACTION ITEM 5 CONTINUED) l i

Since the liquid processed in this subsystem contains only the secondary side drains and leakages, design considerations beyond those employed for the RHUTs are only appropriate for the equipment with concentrating _ capability. The Miscellaneous Liquid Radwaste System, located inside the Auxiliary Building, processes primary side liquids with radioactivity orders of magnitude greater than those in the Radioactiv, Liquid Effluent System. The performance ,

objectives of the Radioactive Liquid Effluent System are the same as those for the Miscellaneous Liquid Radwaste System. As stated in Chapter 11 of the USAR, the systems are designed to reasonably assure that plant personnel and the general public are protected against excessive exposure from radioactive liquid wastes in accordance with limits defined in 10CFR20,10CFR50, and 40CFR190.

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Attachment 1 9 of 9 ACTION ITEM 6:

PROVIDE DESIGN INFORMATION ON ADEQUACY OF SNAP FITTINGS ON DEMINERALIZER.

RESPONSE

Hose couplings in process flow lines (1 1/2") are of the cam 1cck type and are rated at 250 psig. The maximum operating pressure is approximately 100 psig.

The cem lock type coJplings have been used for over five years by Pacific Nuclear (the sJpplier of our Sluiceable Demineralizer) in radwaste applications without any problems. These fittings and the hoses are used in low level radwaste domineralizers, radwaste solidification, and resin transfer systems.

The 1/2" vent and sample lines are provided with Swagelok connectors which are rated at 750 psig.

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